British taxpayers could end up footing the clean-up bill from any major oil spill in UK waters because current rules allow companies to dodge their environmental responsibilities, according to MPs investigating BP's Gulf of Mexico disaster.

And the government ought to require companies to prove that they can pay out billions of pounds in clean-up costs before they are granted exploration and production licences, recommends the committee's final report, which is published today.

It also points to "serious doubts" over whether companies' plans to respond to spills – by capping leaking wells and skimming oil from the sea surface – would work in the rough Atlantic waters off the west coast of Shetland. The report points to the "limitations" of the computer modelling used by oil companies to predict the long-term effects of spills at sea. The Guardian has obtained documents relating to the oil spill response plan of US company Chevron which, in October, was given consent to drill off Shetland. It showed that its modelling software could not simulate spills lasting more than 14 days without crashing. The Gulf of Mexico spill lasted almost three months.

The energy and climate change committee held several hearings last year, with witnesses from the oil industry – including BP's former chief executive Tony Hayward – environmentalists and politicians all giving evidence. Its report (UK Deepwater Drilling: Implications of the Gulf of Mexico Oil Spill) into what lessons could be learned from the BP disaster largely exonerates the UK's industry and regulatory regime, which it said was much tougher than the one that oversaw the Gulf of Mexico.

But it attacks the voluntary oil spill clean-up fund set up by the industry, which can pay out a maximum of $250m (£161m) per year, as "insufficient". It only covers "direct damage" the definition of which the report says is not clear. "While membership of the Offshore Pollution Liability Association [Opol] remains voluntary ... [that] voluntary nature weakens its legality and the control and deployment of its funds. We believe this lack of legal control will allow polluters to claim that damages to biodiversity and ecosystems are indirect, and therefore do not qualify for compensation."

The report adds: "We conclude there needs to be clarity on the identity and hierarchy of liable parties to ensure that the government, and hence the taxpayer, do not have to pay for the consequences of offshore incidents."

The report also says that EU legislation obliging companies to meet their responsibilities over a spill is vague and inconsistent and "unlikely to bring to account those responsible for environmental damage caused by an offshore incident such as happened in the Gulf of Mexico". It adds that the government should work with the EU to draw up new legislation based on the "polluter pays" principle.

It says that a moratorium on drilling in the UK, as some environmentalists have recommended, would be bad for the British economy. In December Barack Obama, the US president, angered the oil industry when he banned new drilling off the east coast and the eastern part of the Gulf of Mexico.

However, the committee, which is chaired by Tim Yeo, the Conservative MP and former environment minister, said that the British regulator should consider requiring all blow-out preventers to have a double, rather than a single, set of blind shear rams, which are supposed to cut through the drill pipe to close off the well in the event of a blow-out. BP's Deepwater Horizon only had one set of blind shear rams, which failed to activate, rendering the blow-out preventer – the last line of defence against a major spill – useless.

Charles Hendry, the energy minister, said that the government would carry out another review of the British offshore safety regime once US investigations had been concluded. Trade body Oil and Gas UK said it was against a requirement for double shear rams and disagreed on the report's claims on industry clean up funding.

The report also urges the government and oil companies to stop the intimidation of rig workers into not reporting safety concerns. The Health and Safety Executive (HSE) accused Transocean, the American rig owner at the centre of BP's Gulf of Mexico oil spill, of compromising safety in the North Sea by "bullying, harassment and intimidation" of its staff.